1. Field of the Invention
The present invention concerns a method for gastric artery chemical embolization making use of an imaging apparatus, as well as an imaging apparatus for implementing such a method.
2. Description of the Prior Art
Obesity is a serious physical illness that has important meaning, not only for the person affected, but also for society as a whole.
In an examination of the body mass index (BMI) distribution conducted in Germany, a rapid increase in BMI in recent years has been observed. Using BMI as an indicator for obesity, approximately a quarter of the population is obese.
The causes of being overweight are numerous. These include a familial disposition to obesity, genetic causes, modern lifestyle, such as lack of exercise and improper nutrition such as high consumption of protein-dense foods, fast food, sugar-containing drinks, and alcoholic beverages. Other sources of obesity are chronic stress, eating disorders, endocrine disorders such as hypothyroidism and Cushing syndrome, pharmaceuticals such as antidepressants, neuroleptics, anti-diabetics, beta blockers, etc. Other causes are enforced immobility, pregnancy, surgery in the hypothalamus region, and nicotine withdrawal.
Obesity is not always the result of a lack of self-discipline or abstinence on the part of the individual, as may sometimes be assumed by laymen, or even physicians. Obesity can be caused by a complex interaction of environmental factors, behavior-related factors, and genetic/biological bases.
Conventional treatments for obesity usually involve, as a first resort, a long-term adjustment of the nutrition and lifestyle habits of the patient. In order for such a treatment to be effective, the patient must be actively involved and must accept the fact that he or she has a weight problem, and must commit to the physician's instructed treatment. In such situations, however, caution is suggested in the case of pregnancy, lactation, or severe general illnesses. In such cases, this type of conventional treatment of obesity should be postponed until the general health of the patient improves.
Cornerstones of conventional obesity therapy are diet counseling, which includes calorie reductions, behavioral therapy, which may include relearning responses to feelings of hunger and satiation, and they also involve stress reduction and addressing eating disorders. A further cornerstone of conventional treatment is regular physical training and exercise.
Although subject to considerable variations, if and when body mass index is considered to be a reliable indicator of obesity, it is generally considered that a person with a BMI of 30 or more should be counseled to lose weight.
Overweight individuals can achieve significant health advantages by a reduction in weight. Lowering cholesterol level and the risk of related illnesses are beneficial. Among such illnesses are, for example, coronary heart disease, high blood pressure and arterial sclerosis. The risk of developing type 2 diabetes also drops significantly with weight reduction.
For persons for whom the aforementioned conventional treatment does not achieve meaningful results, a further option, implemented only by consultation with a knowledgeable physician, is a pharmaceutical treatment.
Pharmaceuticals such as the appetite suppressants Sibutramine and Rimonabant have previously been used for treating obesity. These appetite suppressants modify the brain metabolism and intensify the feeling of satiation. Such appetite suppressants, however, often lead to significant side effects, particularly if the patient has pre-existing cardiovascular disease. For these reasons, Rimonabant is no longer permitted for treatment of obesity. The approval for Sibutramine for obesity treatment has currently lapsed, and pharmaceuticals containing Sibutramine can no longer be dispensed through pharmacies. The manufacturer of that pharmaceutical has removed it from the market. Over the counter tablets with the active substance Orlistat are available for addressing obesity. Orlistat has previously been available only by prescription. This pharmaceutical inhibits the fat-digesting enzymes in the intestine, and thus reduces fat absorption. As a result, only a portion of the ingested fat is actually digested. The undigested portion of the fat exits the body. Among side effects of this pharmaceutical are diarrhea and increased flatulence. Moreover, such diet pills are effective only if the calorie intake is simultaneously limited and regular exercise is scheduled. Such diet pills are not a replacement for exercise or proper diet.
A very last resort to treating obesity, again to be considered only after consultation with a physician, is surgery. Surgery is generally considered as a viable alternative to extremely obese subjects, such as those having a BMI of 40 or more, or patients having a BMI of 35 or more who have significant related illnesses, such as type 2 diabetes. Surgery should only be considered as an option after exhausting all avenues of more conservative treatments.
Commonly available surgical procedures include reducing the size of the stomach (gastroplasty), and reducing the size of the entrance to the stomach with an adjustable stomach band. In this type of surgery, an adjustable silicone band is placed around the fundus of the stomach in a laparoscopic procedure. The diameter of the opening can be adjusted by selectively filling the band with a fluid. For this purpose, access to the band (i.e., a port) must be provided in the stomach wall or in the front of the sternum. A constriction of the stomach diameter thereby takes place in the intake region, and a long-term, significant weight reduction can be achieved.
Another surgical option is the implantation of a stomach balloon, which occupies a volume within the stomach that would otherwise be occupied by ingested food, thereby producing an artificial feeling of satiation.
Other surgical options involve intestinal procedures that produce a modified nutrient absorption.
Another surgical option has been recently developed that is a minimally invasive procedure that has shown success in animal experiments. This is known as the GACE procedure, and is described in “Catheter-Directed Gastric Artery Chemical Embolization Suppresses Systemic Ghrelin Levers in Porcine Model,” Arepally, Radiology, Volume 249, No. 1 (2008).
In this procedure, a catheter is introduced via the femoral artery into the gastric artery. The gastric artery is an artery of the abdominal cavity in the region of the epigastrium, and essentially supplies the fundus of the stomach with blood.
The fundus is the dome-shaped, curved portion of the stomach that is situated next to, and to the left of, the stomach entrance (cardia). Air that is unavoidably swallowed with ingestion normally collects at this location. The fundus glands are found in the gastric mucosa of this portion of the stomach.
In the GACE procedure, a chemo-embolization of the gastric artery takes place via the catheter, thereby reducing the production of the hormone ghrelin, which is significantly produced in the cells of the walls of the fundus, and stimulates the feeling of hunger.
Initial results with the GACE procedure have shown that the feeling of hunger is reduced by the chemo-embolization, thereby leading to a decrease in weight.
A disadvantage of the GACE procedure is that the vascular supply of the fundus includes many overlapping vessels for blood supply to other organs, such as the liver. If the gastric artery is not properly targeted for the chemo-embolization, this can lead to an insufficient, incomplete or even an incorrect embolization. Conventional x-ray techniques such as fluoroscopy and 2D angiography have not been found to be satisfactory for reliably implementing the GACE procedure. This current situation has impaired the success rate of GACE procedures that have been implemented, and may possibly result in damage to other organs.